In the manufacture of the semiconductor device, a desired device is produced by repeatedly performing various processes such as an etching process, a film forming process and the like onto a semiconductor wafer (hereinafter, simply referred to as “wafer”) that is a substrate.
Conventionally, as a substrate processing apparatus, a single wafer processing apparatus in which one wafer is processed at a time has been widely used. This processing apparatus is required to improve throughput, and there has been proposed a processing apparatus that processes two or more substrates at a time while maintaining a flatform of a single wafer processing type (see, e.g., Japanese Patent Application Publication Nos. 2010-520649 and 2012-015285).
In substrate processing apparatuses disclosed in Japanese Patent Application Publication Nos. 2010-520649 and 2012-015285, one substrate mounting table is provided in a chamber, a gas dispersion plate forming a single shower shape is provided above the substrate mounting table to face the substrate mounting table, a plurality of (two) substrates is mounted on the substrate mounting table, the inside of the chamber is maintained in a vacuum state, a processing gas is supplied from the gas dispersion plate, and then a predetermined process is performed on the substrates.
In a substrate process such as an etching process and the like, along with an increased size of a substrate, it is getting difficult to secure uniformity of the process but the demand for the process uniformity is getting increased. However, in the technology disclosed in Japanese Patent Application Publication Nos. 2010-520649 and 2012-015285, it is difficult to acquire desired process uniformity. Specifically, in the technology disclosed in Japanese Patent Application Publication Nos. 2010-520649 and 2012-015285, ununiformity in temperature or gas supply is generated by the interference between substrates, thereby making it difficult to obtain enough process uniformity. Further, even in a general single wafer processing apparatus, enough uniformity in the process may not be obtained.